Donald Trump on Wednesday slammed what he described as “thugs” and “criminals” who clashed with police outside an Albuquerque campaign event, just hours after police in riot gear and mounted patrol units faced off against the violent crowd.

Trump’s supporters responded with chants of “Build that wall!” At one point, a female protester was physically dragged from the stands by security. Other protesters scuffled with security as they resisted removal from the convention center.

The altercations left a glass door at the entrance of the convention center smashed. During the rally, protesters outside overran barricades and clashed with police in riot gear. They also burned T-shirts and other items labeled with Trump’s catchphrase, “Make America Great Again.”